Funfetti Birthday Cake

Preheat oven to 350°F. Spray a quarter sheet pan (large baking sheet) with baking spray. Line the bottom of the pan with parchment paper. Set aside.

With an electric mixer or in the bowl of a stand mixer, cream together butter and sugar until fluffy. Add egg whites, one at a time, mixing well after each one. Mix in vanilla and oil.

In a medium bowl, whisk together cake flour, baking powder, and salt. With mixer running on low, add this to the butter mixture in three additions, alternating with the milk.

Once you have a smooth batter, fold in pastel coloured quins with a rubber spatula. Spread batter in the prepared sheet pan.

Bake for about 25 minutes, until cake is puffed and center is no longer jiggly (cake should bounce back when lightly poked with your finger.) Transfer to a wire cooling rack and let cool completely.

With an electric mixer or in the bowl of a stand mixer fitted with the paddle attachment, prepare the buttercream. Beat butter on medium speed until smooth. Turn mixer to low and gradually add sugar, 1 cup at a time, mixing until incorporated. Scrape down the sides of the bowl and add vanilla, heavy cream and salt. Mix on medium until smooth and creamy. At this point you can check the firmness of the buttercream to get it how you would like: if it’s too firm, add in some more cream (1 teaspoon at a time), and if it’s not firm enough, add more powdered sugar (1 tablespoon at a time). Add pastel coloured quins or jimmies and mix until evenly spread.

To assemble the cake, use a 6-inch cake ring to cut out 3 circles from the cake (see note).

Place 1 cake layer on your cake stand or serving plate. Evenly cover the top with frosting. Top with second layer and evenly cover the top with frosting. Top with third layer and top with frosting. Lightly spread the frosting around the sides of the cake (for a dirty icing) and then pop the entire cake in the freezer for 10 minutes. Continue frosting the cake along the sides and top until completely covered and smooth.

Decorate top of cake with extra pastel coloured quins, if desired. Slice, serve, enjoy!

Recipe adapted from Molly on Food52.

Notes:
1. Do not use sprinkles that will dye your batter, like nonpareils, which are the little balls. Rainbow jimmies or pastel coloured quins are fine.
2. Save the rest of the cake to enjoy on its own. I like to cut it into squares and spread with any remaining frosting for lunches during the week.
3. The buttercream used in this recipe will begin to dry out and develop a crust over time. If not using immediately, briefly re-mix before use.